It is known to attach an air bag module to the hub portion of a vehicle steering wheel. Often, the air bag module can be pressed downward relative to the steering wheel to actuate a vehicle horn. In such systems, it is desirable that the vehicle horn be actuated regardless of the location on the air bag module at which a downward force is applied. It is common for the air bag module to become tilted relative to the steering wheel when pressed downward at a location adjacent an edge of the air bag module. Gaps between the air bag module and the surrounding structure of the steering wheel must be maintained large enough to permit the air bag module to actuate the vehicle horn when the air bag module tilts.
It is desirable to reduce the size of the gaps between the air bag module and the surrounding structure of the steering wheel. The reduction in size of the gaps, however, must not obstruct the downward movement of the air bag module relative to the steering wheel for actuating the vehicle horn. Reducing the tendency of the air bag module to tilt relative to the steering wheel enables the gaps to be reduced in size.
It is also desirable for the vehicle horn to be actuated by a substantially uniform downward force regardless of the location on the air bag module at which the downward force is applied. For example, it is desirable for the downward force necessary to actuate the vehicle horn when the force is applied at an edge of the air bag module to be substantially equal to the downward force necessary to actuate the vehicle horn when the force is applied at a central location of the air bag module. This also may be accomplished by reducing the tendency of the air bag module to tilt relative to the steering wheel. When the tendency of the air bag module to tilt is reduced, a downward force that is applied, for example, at an edge of the air bag module tends to remain directed substantially downward and less of the force is directed transverse to the downward direction. As a result, the downward force necessary to actuate the vehicle horn becomes substantially equal regardless of the location on the air bag module at which the downward force is applied.